Casting of ingots



May 29, 1928.

C. A. PARSONS ET AL CASTING OF INGOTS Filed Oct. 1927 Patented May 29,192 8.

UNITED STATES 1,671,253 PATENT OFFICE.

. cmLns ALenRNoN FARSONS A D HUGH MALCOLM DUNCAN, or NEWCASTLE-N- TYNE,ENGLAND; SAID DUNCAN ASSIGNOR T0 SAID PARSONS.

CASTING or INGors.

Application filed October 6, 1927, Serial No. 224,453, and in GreatBritain April 29, 1926.

The invention relates to the casting of steel ingots.

In casting steel ingots, difficulties arlse I in connection with thesegregation of certain elements such as carbon, sulphur and phosphorusand also in connection withthe looseness of structureabout the centralaxis of the ingot and the main object of the resent invention is toovercome or assist in overcoming such difficulties so as to se cureingots of, greater homogeneity and soundness.

With the object indicated 7 The invention consists. in a process ofcasting steel ingots comprising pour ng the molten metal into a mouldhaving its longitudinal dimensions greater than its vertical, thickrefractory material cover ng the sides of said mould and a bottom chillof large dimensions preferably of metal, preheating the mould to a hightemperature of the order of molten steel before pouring the metaltherein, and continuously supplying.

heat to the upper surface of the molten metal after casting so that theupper' layer is the last to solidify.

The invention also consists in the process of casting steel ingots to behereinafter described or indicated. J

The accompanying drawing shows a diagrammatic sectional elevation of onestructural form of the invention by way of example.

In carrying' the invention into efiect according to this form, the mouldconsists of a strong sheet steel casing, a, slightly conical in form asshown and reinforced by heavy angles, b, top and bottom. The casing islined with shaped firebrick quoins, d, closely fitted together and tothe outer casing and is preferably provided with lift ing eyes, a,riveted to the sides.

heat to the surface of the metal after ing it with its cover in place onthe top of an adjoiningfirebrick table containing suitable gas or oilburners delivering flame upwards. If desired the burners, 1', may beused for preheating the mould.

The cover is also provided with a hole,

I, for use when pouring. The chilled block, m, may be of cast iron orsteel formed of one or more pieces fitted together and preferablyprotected on. its upper surface against the wash of the molten steel bya thin steel plate, a, which is easily renewable.

The chill block may be artificially cooled in any well-known way such asby gills, or supporting ribs, cast on the underside and integral withthe block, and traversed by artificial airblast.

It is evident that by varying the duration and intensity of heating andthe thickness and insulating quality of the firebrick of the mould, anydesired rate of cooling of the sides of the ingot can be obtained andthat further in some cases it may be found desirable to thicken thefirebrick and form heating fiues and burners within it or provide othermeans of heating such as electrically heated coils.

The internal surface of the mould must be kept as smooth as possiblewith any suit-. able wash, such as clay, graphite, carborundum or thelike, so as to part freel from the ingot after it has sufiicientlycooled and contracted.

According to the form shown in the drawing, the breadth or diameter ofthe ingot, o, is twice the height, but this ratio may be variedaccording to the size of the ingot, the facilities available for for ingit and the final characteristics'desire in the finished forging. I

7 By means of the apparatus described, cooling of the-ingot due to theheat capacity of the massive metal base, m, and the use of the burner orburners, 7', takes place 1 from the bottom upwards with the isothermalslying approximately in horizontal planes.

When the ingot 'is sufficiently set the mould is removed by a crane inthe ordi- 105 nary way, leaving the ingot standing on the block.

By virtue of the invention the segregates are distributed more evenlythroughout the ingot while in addition, due to the molten no metalsolidifying more nearly at the same time throughout the cross section ofthe ingot, axial weakness or looseness of struc-.

Weighing 2 tons 14 cwt. cast in accordance with the methods abovedescribed by help of a base block Weighing 10 tons, was found onexamination to be sound throughout and of great chemical homogeneity. 1

Having now described our invention, what we claim as new and desire tosecure by Letters Patent is A process of casting steel ingots whichcomprises preheating the walls of a mold to a high temperature of theorder of molten steel before pouring the metal therein, whilemaintaining the mold chill relatively cool, pouring the molten metalinto the mold to form a pool having its longitudinal dimensions greaterthan its vertical, and continuously supplying heat to the upper surfaceof the molten metal after casting so tlfiat the upper surface is thelast to solid- 1 y. I

In testimony whereof we have signed our names to this specification.

CHARLES ALGERNON PARSONS.

HUGH MALCOLM DUNCAN.

